In recent years, in mobile terminals such as mobile phones, as a member that detects a contact by an operator, electronic devices with a touch sensor such as a touch panel, a touch switch and the like are increasing. Further, besides mobile terminals, electronic devices with a touch panel like equipment such as calculators, ticket vending machines and the like, home appliances such as microwaves, TV sets, lighting equipment and the like, and industrial equipment (FA equipment) and the like are widely used.
A variety of touch sensors have been proposed so far (see, for example, Patent Document 1). The Patent Document 1 proposes an analog type resistive film touch panel that can be produced at a low cost and miniaturized. The touch panel described in Patent Document 1 is configured using two conductive films slightly spaced therebetween by a spacer. In this touch panel, when the conductive films are pushed and come in contact each other, the position of the contact is read as a voltage by one conductive film, based on the voltage gradient applied to the other conductive film.
As such a touch sensor, in addition to a resistive film type, a variety of types such as a capacitive type and an optical type are known. These types of touch sensors detect a contact by the operator's finger, a stylus pen and the like. An electronic device with a touch sensor generally displays images such as operation keys, buttons and the like (hereinafter referred to as “object”) on a display unit such as a liquid crystal display disposed on the back face side of the touch sensor. When the operator executes operations of touching the object displayed on the display unit, the touch on the position corresponding to the object is detected by the touch sensor.
In the electronic device with such a touch sensor, according to the application software (hereinafter referred to merely as “application”) to be used, a variety of user interfaces can be configured by displaying a variety of objects. Thus, in the electronic device with a touch sensor, a variety of user interfaces can be configured at a high degree of freedom. Such an electronic device is easy to operate and user friendly, and thus an electronic device with a touch sensor has spread rapidly.
Further, recently, the performance of the touch sensor mounted on an electronic device has been improved and, for example, like a touch sensor for multi-touch, some touch sensors can, even if a plurality of points are touched simultaneously, respectively detect the plurality of points. In addition, as an operation method executed by the operator to the touch sensor, some touch sensors detect not only the presence of contact but also the operation mode by the contact, thereby performing a variety of different processes according to the operation mode (see, for example, Patent Document 2).
For example, some electronic devices can detect a variety of operation modes such as, for example, tap on a touch sensor only once (single tap), quick twice tap (double tap), slide (or drag) for moving a position of the touch while touching a touch sensor, flick for quick sliding, and the like. Further, in the case of a touch sensor for multi-touch, some of such touch sensors can detect a pinching operation in which the operator simultaneously touches the touch sensor with his/her two fingers and pinches/spreads these two fingers. In this case, an operation of spreading the two fingers touching the touch sensor can be called “a pinch out operation” and an operation of pinching the two fingers can be called “a pinch in operation.”
Recently, for example, as with smart phones, tablet computers and the like, high performance and multifunctional electronic devices with a touch sensor are in widespread use, and accordingly, a greater importance is put on the technique for detecting various operations to the touch sensor by the operator.